1. Field of the Invention
The present invention relates to an elliptical exercise machine, and more particularly to an elliptical exercise machine including an adjustable structure for allowing the elliptical exercise machine to be easily adjusted to different moving strokes and for allowing the elliptical exercise machine to be easily operated by the user.
2. Description of the Prior Art
Typical elliptical exercise machines comprise a pair of foot supports pivotally coupled to a supporting base with cranks and slidably attached to the supporting base with wheels or rollers for allowing the elliptical exercise machine to be moved in an elliptical moving stroke.
For example, U.S. Pat. No. 5,352,169 to Eschenbach, and U.S. Pat. No. 5,595,553 to Rodgers, Jr. disclose two of the typical elliptical exercise machines each also comprising a pair of cranks rotatably supported on a supporting base and pivotally coupled to two foot supports which are slidably attached to the supporting base with wheels or rollers for allowing the elliptical exercise machine to be moved in an elliptical moving stroke.
However, the moving strokes of the elliptical exercise machines may not be adjusted to different moving strokes and may not be easily operated by different users.
U.S. Pat. No. 5,823,917 to Chen, U.S. Pat. No. 6,053,847 to Stearns et al., and U.S. Pat. No. 6,077,198 to Eschenbach disclose three further typical elliptical exercise machines each also comprising a pair of cranks rotatably supported on a supporting base and pivotally coupled to two foot supports which are slidably attached to the supporting base with wheels or rollers or other pivotal structures for allowing the elliptical exercise machine to be moved in an elliptical moving stroke. The typical elliptical exercise machines each comprise an adjustable structure for allowing the elliptical exercise machine to be adjusted to different moving strokes.
However, the adjustable structures of the elliptical exercise machines include a motorized or complicated configuration that may not be easily operated by different users.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional elliptical exercise machines.